This invention is in the field of trocars and apparatus for inserting trocars inwardly through an abdominal wall or other anatomical wall of a patient. Traditionally trocars have been inserted manually by a surgeon who holds the trocar in his hand or hands (a male is assumed merely for convenience of terminology herein) and directs the point of the obturator to a site on the surface of the abdomen which surface is prepared by forming a small straight line incision or X-shaped cut. The obturator is forcibly pushed in the axial direction through the skin and layers of muscle, fascia and peritoneum.
At the time of insertion the outer surface of the abdominal wall is either flat or somewhat convex as the patient lies on his back, and the trocar is inserted generally perpendicularly to that surface. For reasons as discussed below more fully, it is quite dangerous for the obturator to be inserted perpendicular to the surface without exercise of great control, because when the tip or point of the obturator penetrates this wall and enters the abdominal cavity it could easily nick, cut or otherwise damage an organ below.
One technique used by surgeons is to engage the abdominal wall with one hand, grasping a considerable portion of tissue and turning this mass of tissue somewhat transversely to adjacent portions of the abdominal wall, and then with the other hand aiming and inserting the trocar obturator through the wall in such a way that it travels in a direction generally parallel to the outer surface of the abdomen. This forcible penetration through a distorted tissue mass is awkward and greatly lacking in precise control over the process of insertion since the surgeon is pushing very hard against a resistance that cannot be precisely measured or predicted.
One device previously developed by the applicant herein for trocar insertion is an electrical power driven gun type apparatus which holds and forcibly directs a trocar by oscillating the trocar while directing it axially. In contrast to a surgeon manually pushing a trocar solely by the power in his hands, arms and upper body, this electrical power device provides a substantial amount of measured control during axial insertion, and also removes from the surgeon the necessity for using his own muscle power since the gun motor does most of the work. Also, by the gun's mechanism the axial motion is specific and controlled to be incremental, such that axial motion can be stopped very quickly at any time it is determined that the tip had penetrated the inner layer of the abdominal wall or the surgeon decides to stop for any reason. It is most difficult or impossible for a surgeon to stop forward motion in the midst of his own manual thrust with standard trocars.
The disadvantage of the above-described electro-mechanical apparatus is primarily its cost of manufacture. While the apparatus itself is very useful and operates as intended, the cost is a problem to hospital administrators who are concerned with economics of surgical procedures while seeking maximum use of new and better instruments.
Accordingly, the device of the present invention was developed to achieve insertion of a trocar with a minimum of physical effort by the surgeon since he will be using mechanical advantage achieved through the mechanism, and with a maximum control during the axial motion so that the above-described dangers are greatly minimized or reduced, while reducing cost of manufacture. Thus, it was desired that such new mechanism provide the advantages of the prior electro-mechanical device, but do so with a minimum of parts and cost of manufacture. This is especially true for hospitals which require these apparatus to be disposable. While it is obviously desirable for these and other surgical instruments to be autoclavable or otherwise sterilizable and reused, such is not always feasible or acceptable in this era of concern about AIDS and other transmittable diseases and infections. Accordingly, many people feel strongly that such instruments should be disposable. The present invention is a very simple, reliable, economical and totally mechanical device for holding and inserting a trocar, as disclosed and described herein.